A novel regulatory pathway of transcriptional activation by mRNA cap-binding complex in vivo.

摘要

In this thesis, we have explored two related aspects of eukaryotic gene regulation - (i) role of cap-binding complex (CBC) in transcription, and (ii) regulation of histone H3-K56 acetylation and its function in gene expression.;CBC binds to the mRNA cap structure to protect it from exonucleases. Intriguingly, CBC also regulates the downstream events such as RNA splicing, 3'-end formation and export. However, whether CBC plays a crucial role in controlling the upstream events such as transcriptional initiation or elongation, remains unknown. Here, we demonstrate that CBC stimulates the formation of the pre-initiation complex assembly at the active gene (and hence transcriptional initiation) in a positive feedback manner in Saccharomyces cerevisiae, thus providing a novel function of CBC in eukaryotic gene regulation.;In the second part, we have defined Rtt109p as a novel regulator of H3-K56 acetylation that is involved in maintaining genome stability, but not gene expression.